<?php
/*************************
  Coppermine Photo Gallery
  ************************
  Copyright (c) 2003-2008 Dev Team
  v1.1 originally written by Gregory DEMAR

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License version 3
  as published by the Free Software Foundation.
  
  ********************************************
  Coppermine version: 1.4.19
  $HeadURL: https://coppermine.svn.sourceforge.net/svnroot/coppermine/trunk/cpg1.4.x/include/exif.php $
  $Revision: 4392 $
  $Author: gaugau $
  $Date: 2008-04-16 09:25:35 +0200 (Mi, 16 Apr 2008) $
**********************************************/

/*
//================================================================================================
//================================================================================================
//================================================================================================
/*
  Exifer 1.5
  Extracts EXIF information from digital photos.

  Copyright  2005 Jake Olefsky
  http://www.offsky.com/software/exif/index.php
  jake@olefsky.com

  This program is free software; you can redistribute it and/or modify it under the terms of
  the GNU General Public License as published by the Free Software Foundation; either version 2
  of the License, or 

  This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the GNU General Public License for more details. http://www.gnu.org/copyleft/gpl.html

  SUMMARY:
        This script will correctly parse all of the EXIF data included in images taken
        with digital cameras.  It will read the IDF0, IDF1, SubIDF and InteroperabilityIFD
        fields as well as parsing some of the MakerNote fields that vary depending on
        camera make and model.  This script parses more tags than the internal PHP exif
        implementation and it will correctly identify and decode what all the values mean.

        This version will correctly parse the MakerNote field for Nikon, Olympus, and Canon
        digital cameras.  Others will follow.

  TESTED WITH:
        Nikon CoolPix 700
        Nikon CoolPix 4500
        Nikon CoolPix 950
        Nikon Coolpix 5700
        Canon PowerShot S200
        Canon PowerShot S110
        Olympus C2040Z
        Olympus C960
        Canon Ixus
        Canon EOS 300D
        Canon Digital Rebel
        Canon EOS 10D
        Canon PowerShot G2
        FujiFilm DX 10
        FujiFilm MX-1200
        FujiFilm FinePix2400
        FujiFilm FinePix2600
        FujiFilm FinePix S602
        FujiFilm FinePix40i
        Sony D700
        Sony Cybershot
        Kodak DC210
        Kodak DC240
        Kodak DC4800
        Kodak DX3215
        Ricoh RDC-5300
        Sanyo VPC-G250
        Sanyo VPC-SX550
        Epson 3100z

  If you improve this script or test it with a camera not on my list, please email me a copy of
  the improvement so everyone can benefit from it.  Thanks!


  VERSION HISTORY:

  1.0   Sept 23, 2002

      First Public Release

  1.1   Jan 25, 2003

      +Gracefully handled the error case where you pass an empty string to this library
      +Fixed an inconsistency in the Olympus Camera parsing module
      +Added support for parsing the MakerNote of Canon images.
      +Modified how the imagefile is opened so it works for windows machines.
      +Correctly parses the FocalPlaneResolutionUnit and PhotometricInterpretation fields
      +Negative rational numbers are properly displayed
      +Strange old cameras that use Motorola endineness are now properly supported
      +Tested with several more cameras

      Potential Problem: Negative Shorts and Negative Longs may not be correctly displayed, but I
        have not yet found an example of negative shorts or longs being used.

  1.2   Mar 30, 2003

      +Fixed an error that was displayed if you edited your image with WinXP's image viewer
      +Fixed a bug that caused some images saved from 3rd party software to not parse correctly
      +Changed the ExposureTime tag to display in fractional seconds rather than decimal
      +Updated the ShutterSpeedValue tag to have the units of 'sec'
      +Added support for parsing the MakeNote of FujiFilm images
      +Added support for parsing the MakeNote of Sanyo images
      +Fixed a bug with parsing some Olympus MakerNote tags
      +Tested with several more cameras

  1.3   Jun 15, 2003

      +Fixed Canon MakerNote support for some models
        (Canon has very difficult and inconsistent MakerNote syntax)
      +Negative signed shorts and negative signed longs are properly displayed
      +Several more tags are defined
      +More information in my comments about what each tag is
      +Parses and Displays GPS information if available
      +Tested with several more cameras

  1.4   Sept 14, 2003

      +This software is now licensed under the GNU General Public License
      +Exposure time is now correctly displayed when the numerator is 10
      +Fixed the calculation and display of ShutterSpeedValue, ApertureValue and MaxApertureValue
      +Fixed a bug with the GPS code
      +Tested with several more cameras

  1.5   Feb 18, 2005

      +It now gracefully deals with a passed in file that cannot be found.
      +Fixed a GPS bug for the parsing of Altitude and other signed rational numbers
      +Defined more values for Canon cameras.
      +Added "bulb" detection for ShutterSpeed
      +Made script loading a little faster and less memory intensive.
      +Bug fixes
      +Better error reporting
      +Graceful failure for files with corrupt exif info.
      +QuickTime (including iPhoto) messes up the Makernote tag for certain photos (no workaround yet)
      +Now reads exif information when the jpeg markers are out of order
      +Gives raw data output for IPTC, COM and APP2 fields which are sometimes set by other applications
      +Improvements to Nikon Makernote parsing
*/
//================================================================================================
//================================================================================================
//================================================================================================




//================================================================================================
//================================================================================================
// Converts from Intel to Motorola endien.  Just reverses the bytes (assumes hex is passed in)
//================================================================================================
//================================================================================================
function intel2Moto($intel) {
  $len = strlen($intel);
  $moto="";
  for($i=0; $i<=$len; $i+=2) {
    $moto.=substr($intel,$len-$i,2);
  }
  return $moto;
}

//================================================================================================
//================================================================================================
// Looks up the name of the tag
//================================================================================================
//================================================================================================
function lookup_tag($tag) {
  switch($tag) {

      //used by IFD0 "Camera Tags"
    case "000b": $tag = "ACDComment";break;           //text string up to 999 bytes long
    case "00fe": $tag = "ImageType";break;            //integer -2147483648 to 2147483647
    case "0106": $tag = "PhotometricInterpret";break;     //?? Please send sample image with this tag
    case "010e": $tag = "ImageDescription";break;       //text string up to 999 bytes long
    case "010f": $tag = "Make";break;             //text string up to 999 bytes long
    case "0110": $tag = "Model";break;              //text string up to 999 bytes long
    case "0112": $tag = "Orientation";break;          //integer values 1-9
    case "0115": $tag = "SamplePerPixel";break;         //integer 0-65535
    case "011a": $tag = "xResolution";break;          //positive rational number
    case "011b": $tag = "yResolution";break;          //positive rational number
    case "011c": $tag = "PlanarConfig";break;         //integer values 1-2
    case "0128": $tag = "ResolutionUnit";break;         //integer values 1-3
    case "0131": $tag = "Software";break;           //text string up to 999 bytes long
    case "0132": $tag = "DateTime";break;           //YYYY:MM:DD HH:MM:SS
    case "013b": $tag = "Artist";break;             //text string up to 999 bytes long
    case "013c": $tag = "HostComputer";break;         //text string
    case "013e": $tag = "WhitePoint";break;           //two positive rational numbers
    case "013f": $tag = "PrimaryChromaticities";break;      //six positive rational numbers
    case "0211": $tag = "YCbCrCoefficients";break;        //three positive rational numbers
    case "0213": $tag = "YCbCrPositioning";break;       //integer values 1-2
    case "0214": $tag = "ReferenceBlackWhite";break;      //six positive rational numbers
    case "8298": $tag = "Copyright";break;            //text string up to 999 bytes long
    case "8649": $tag = "PhotoshopSettings";break;        //??
    case "8825": $tag = "GPSInfoOffset";break;
    case "9286": $tag = "UserCommentOld";break;         //??
    case "8769": $tag = "ExifOffset";break;           //positive integer

      //used by Exif SubIFD "Image Tags"
    case "829a": $tag = "ExposureTime";break;         //seconds or fraction of seconds 1/x
    case "829d": $tag = "FNumber";break;            //positive rational number
    case "8822": $tag = "ExposureProgram";break;        //integer value 1-9
    case "8824": $tag = "SpectralSensitivity";break;      //??
    case "8827": $tag = "ISOSpeedRatings";break;        //integer 0-65535
    case "9000": $tag = "ExifVersion";break;          //??
    case "9003": $tag = "DateTimeOriginal";break;       //YYYY:MM:DD HH:MM:SS
    case "9004": $tag = "DateTimedigitized";break;        //YYYY:MM:DD HH:MM:SS
    case "9101": $tag = "ComponentsConfiguration";break;    //??
    case "9102": $tag = "CompressedBitsPerPixel";break;     //positive rational number
    case "9201": $tag = "ShutterSpeedValue";break;        //seconds or fraction of seconds 1/x
    case "9202": $tag = "ApertureValue";break;          //positive rational number
    case "9203": $tag = "BrightnessValue";break;        //positive rational number
    case "9204": $tag = "ExposureBiasValue";break;        //positive rational number (EV)
    case "9205": $tag = "MaxApertureValue";break;       //positive rational number
    case "9206": $tag = "SubjectDistance";break;        //positive rational number (meters)
    case "9207": $tag = "MeteringMode";break;         //integer 1-6 and 255
    case "9208": $tag = "LightSource";break;          //integer 1-255
    case "9209": $tag = "Flash";break;              //integer 1-255
    case "920a": $tag = "FocalLength";break;          //positive rational number (mm)
    case "9213": $tag = "ImageHistory";break;         //text string up to 999 bytes long
    case "927c": $tag = "MakerNote";break;            //a bunch of data
    case "9286": $tag = "UserComment";break;          //text string
    case "9290": $tag = "SubsecTime";break;           //text string up to 999 bytes long
    case "9291": $tag = "SubsecTimeOriginal";break;       //text string up to 999 bytes long
    case "9292": $tag = "SubsecTimeDigitized";break;      //text string up to 999 bytes long
    case "a000": $tag = "FlashPixVersion";break;        //??
    case "a001": $tag = "ColorSpace";break;           //values 1 or 65535
    case "a002": $tag = "ExifImageWidth";break;         //ingeter 1-65535
    case "a003": $tag = "ExifImageHeight";break;        //ingeter 1-65535
    case "a004": $tag = "RelatedSoundFile";break;       //text string 12 bytes long
    case "a005": $tag = "ExifInteroperabilityOffset";break;   //positive integer
    case "a20c": $tag = "SpacialFreqResponse";break;      //??
    case "a20b": $tag = "FlashEnergy";break;          //positive rational number
    case "a20e": $tag = "FocalPlaneXResolution";break;      //positive rational number
    case "a20f": $tag = "FocalPlaneYResolution";break;      //positive rational number
    case "a210": $tag = "FocalPlaneResolutionUnit";break;   //values 1-3
    case "a214": $tag = "SubjectLocation";break;        //two integers 0-65535
    case "a215": $tag = "ExposureIndex";break;          //positive rational number
    case "a217": $tag = "SensingMethod";break;          //values 1-8
    case "a300": $tag = "FileSource";break;           //integer
    case "a301": $tag = "SceneType";break;            //integer
    case "a302": $tag = "CFAPattern";break;           //undefined data type

    case "a401": $tag = "CustomerRender";break;         //values 0 or 1
    case "a402": $tag = "ExposureMode";break;         //values 0-2
    case "a403": $tag = "WhiteBalance";break;         //values 0 or 1
    case "a404": $tag = "DigitalZoomRatio";break;       //positive rational number
    case "a406": $tag = "SceneCaptureMode";break;       //values 0-3
    case "a407": $tag = "GainControl";break;          //values 0-4
    case "a408": $tag = "Contrast";break;           //values 0-2
    case "a409": $tag = "Saturation";break;           //values 0-2
    case "a40a": $tag = "Sharpness";break;            //values 0-2


      //used by Interoperability IFD
    case "0001": $tag = "InteroperabilityIndex";break;      //text string 3 bytes long
    case "0002": $tag = "InteroperabilityVersion";break;    //datatype undefined
    case "1000": $tag = "RelatedImageFileFormat";break;     //text string up to 999 bytes long
    case "1001": $tag = "RelatedImageWidth";break;        //integer in range 0-65535
    case "1002": $tag = "RelatedImageLength";break;       //integer in range 0-65535

      //used by IFD1 "Thumbnail"
    case "0100": $tag = "ImageWidth";break;           //integer in range 0-65535
    case "0101": $tag = "ImageLength";break;          //integer in range 0-65535
    case "0102": $tag = "BitsPerSample";break;          //integers in range 0-65535
    case "0103": $tag = "Compression";break;          //values 1 or 6
    case "0106": $tag = "PhotometricInterpretation";break;    //values 0-4
    case "010e": $tag = "ThumbnailDescription";break;     //text string up to 999 bytes long
    case "010f": $tag = "ThumbnailMake";break;          //text string up to 999 bytes long
    case "0110": $tag = "ThumbnailModel";break;         //text string up to 999 bytes long
    case "0111": $tag = "StripOffsets";break;         //??
    case "0112": $tag = "ThumbnailOrientation";break;     //integer 1-9
    case "0115": $tag = "SamplesPerPixel";break;        //??
    case "0116": $tag = "RowsPerStrip";break;         //??
    case "0117": $tag = "StripByteCounts";break;        //??
    case "011a": $tag = "ThumbnailXResolution";break;     //positive rational number
    case "011b": $tag = "ThumbnailYResolution";break;     //positive rational number
    case "011c": $tag = "PlanarConfiguration";break;      //values 1 or 2
    case "0128": $tag = "ThumbnailResolutionUnit";break;    //values 1-3
    case "0201": $tag = "JpegIFOffset";break;
    case "0202": $tag = "JpegIFByteCount";break;
    case "0212": $tag = "YCbCrSubSampling";break;

      //misc
    case "00ff": $tag = "SubfileType";break;
    case "012d": $tag = "TransferFunction";break;
    case "013d": $tag = "Predictor";break;
    case "0142": $tag = "TileWidth";break;
    case "0143": $tag = "TileLength";break;
    case "0144": $tag = "TileOffsets";break;
    case "0145": $tag = "TileByteCounts";break;
    case "014a": $tag = "SubIFDs";break;
    case "015b": $tag = "JPEGTables";break;
    case "828d": $tag = "CFARepeatPatternDim";break;
    case "828e": $tag = "CFAPattern";break;
    case "828f": $tag = "BatteryLevel";break;
    case "83bb": $tag = "IPTC/NAA";break;
    case "8773": $tag = "InterColorProfile";break;

    case "8828": $tag = "OECF";break;
    case "8829": $tag = "Interlace";break;
    case "882a": $tag = "TimeZoneOffset";break;
    case "882b": $tag = "SelfTimerMode";break;
    case "920b": $tag = "FlashEnergy";break;
    case "920c": $tag = "SpatialFrequencyResponse";break;
    case "920d": $tag = "Noise";break;
    case "9211": $tag = "ImageNumber";break;
    case "9212": $tag = "SecurityClassification";break;
    case "9214": $tag = "SubjectLocation";break;
    case "9215": $tag = "ExposureIndex";break;
    case "9216": $tag = "TIFF/EPStandardID";break;
    case "a20b": $tag = "FlashEnergy";break;

    default: $tag = "unknown:".$tag;break;
  }
  return $tag;

}

//================================================================================================
//================================================================================================
// Looks up the datatype
//================================================================================================
//================================================================================================
function lookup_type(&$type,&$size) {
  switch($type) {
    case "0001": $type = "UBYTE";$size=1;break;
    case "0002": $type = "ASCII";$size=1;break;
    case "0003": $type = "USHORT";$size=2;break;
    case "0004": $type = "ULONG";$size=4;break;
    case "0005": $type = "URATIONAL";$size=8;break;
    case "0006": $type = "SBYTE";$size=1;break;
    case "0007": $type = "UNDEFINED";$size=1;break;
    case "0008": $type = "SSHORT";$size=2;break;
    case "0009": $type = "SLONG";$size=4;break;
    case "000a": $type = "SRATIONAL";$size=8;break;
    case "000b": $type = "FLOAT";$size=4;break;
    case "000c": $type = "DOUBLE";$size=8;break;
    default: $type = "error:".$type;$size=0;break;
  }
  return $type;
}

//================================================================================================
//================================================================================================
// Formats Data for the data type
//================================================================================================
//================================================================================================
function formatData($type,$tag,$intel,$data) {

  if($type=="ASCII") {
    //do nothing
  } else if($type=="URATIONAL" || $type=="SRATIONAL") {
    $data = bin2hex($data);
    if($intel==1) $data = intel2Moto($data);

    if($intel==1) $top = hexdec(substr($data,8,8));   //intel stores them bottom-top
    else  $top = hexdec(substr($data,0,8));       //motorola stores them top-bottom

    if($intel==1) $bottom = hexdec(substr($data,0,8));  //intel stores them bottom-top
    else  $bottom = hexdec(substr($data,8,8));      //motorola stores them top-bottom

    if($type=="SRATIONAL" && $top>2147483647) $top = $top - 4294967296;   //this makes the number signed instead of unsigned
    if($bottom!=0) $data=$top/$bottom;
    else if($top==0) $data = 0;
    else $data=$top."/".$bottom;

    if(($tag=="011a" || $tag=="011b") && $bottom==1) { //XResolution YResolution
      $data=$top." dots per ResolutionUnit";
    } else if($tag=="829a") { //Exposure Time
      if($top/10 == 1) $data="1/".round($bottom/10, 0)." sec";
      else $data=$top."/".$bottom." sec";
    } else if($tag=="829d") { //FNumber
      $data="f ".$data;
    } else if($tag=="9204") { //ExposureBiasValue
      $data=$data." EV";
    } else if($tag=="9205" || $tag=="9202") { //ApertureValue and MaxApertureValue
      //ApertureValue is given in the APEX Mode. Many thanks to Matthieu Froment for this code
      //The formula is : Aperture = 2*log2(FNumber) <=> FNumber = e((Aperture.ln(2))/2)
      $data = exp(($data*log(2))/2);
      $data = round($data, 1);//Focal is given with a precision of 1 digit.
      $data="f ".$data;
    } else if($tag=="920a") { //FocalLength
      $data=$data." mm";
    } else if($tag=="9201") { //ShutterSpeedValue
      // The ShutterSpeedValue is given in the APEX mode. Many thanks to Matthieu Froment for this code
      // The formula is : Shutter = - log2(exposureTime) (Appendix C of EXIF spec.)
      // Where shutter is in APEX, log2(exposure) = ln(exposure)/ln(2)
      // So final formula is : exposure = exp(-ln(2).shutter)
      // The formula can be developed : exposure = 1/(exp(ln(2).shutter))
      $data = exp($data * log(2));
      if ($data > 1) $data = floor($data);  //Drop the decimal.
      if ($data > 0) {
        $data = 1/$data; //Final calculation. We now have a floating number. Transform it in a pretty number
        $n=0;$d=0;
        ConvertToFraction($data, $n, $d);
        if ($n>=1 && $d==1) $data = $n." sec"; //To avoid exposure times style 3/1 sec.
        else $data = $n."/".$d." sec";
      } else {
        $data = "Bulb";
      }
    }

  } else if($type=="USHORT" || $type=="SSHORT" || $type=="ULONG" || $type=="SLONG" || $type=="FLOAT" || $type=="DOUBLE") {
    $data = bin2hex($data);
    if($intel==1) $data = intel2Moto($data);
    if($intel==0 && ($type=="USHORT" || $type=="SSHORT")) $data = substr($data,0,4);
    $data=hexdec($data);

    if($type=="SSHORT" && $data>32767) $data = $data - 65536; //this makes the number signed instead of unsigned
    if($type=="SLONG" && $data>2147483647) $data = $data - 4294967296;  //this makes the number signed instead of unsigned

    if($tag=="0112") { //Orientation
      if($data==1) $data = "Normal (O deg)";
      if($data==2) $data = "Mirrored";
      if($data==3) $data = "Upsidedown";
      if($data==4) $data = "Upsidedown Mirrored";
      if($data==5) $data = "90 deg CW Mirrored";
      if($data==6) $data = "90 deg CCW";
      if($data==7) $data = "90 deg CCW Mirrored";
      if($data==8) $data = "90 deg CW";
    } else if($tag=="0128" || $tag=="a210" || $tag=="0128") {  //ResolutionUnit and FocalPlaneResolutionUnit and ThumbnailResolutionUnit
      if($data==1) $data = "No Unit";
      if($data==2) $data = "Inch";
      if($data==3) $data = "Centimeter";
    } else if($tag=="0213") { //YCbCrPositioning
      if($data==1) $data = "Center of Pixel Array";
      if($data==2) $data = "Datum Point";
    } else if($tag=="8822") { //ExposureProgram
      if($data==1) $data = "Manual";
      else if($data==2) $data = "Program";
      else if($data==3) $data = "Aperature Priority";
      else if($data==4) $data = "Shutter Priority";
      else if($data==5) $data = "Program Creative";
      else if($data==6) $data = "Program Action";
      else if($data==7) $data = "Portrat";
      else if($data==8) $data = "Landscape";
      else $data = "Unknown: ".$data;
    } else if($tag=="9207") { //MeteringMode
      if($data==0) $data = "Unknown";
      else if($data==1) $data = "Average";
      else if($data==2) $data = "Center Weighted Average";
      else if($data==3) $data = "Spot";
      else if($data==4) $data = "Multi-Spot";
      else if($data==5) $data = "Multi-Segment";
      else if($data==6) $data = "Partial";
      else if($data==255) $data = "Other";
      else $data = "Unknown: ".$data;
    } else if($tag=="9208") { //LightSource
      if($data==0) $data = "Unknown or Auto";
      else if($data==1) $data = "Daylight";
      else if($data==2) $data = "Flourescent";
      else if($data==3) $data = "Tungsten";
      else if($data==10) $data = "Flash";
      else if($data==17) $data = "Standard Light A";
      else if($data==18) $data = "Standard Light B";
      else if($data==19) $data = "Standard Light C";
      else if($data==20) $data = "D55";
      else if($data==21) $data = "D65";
      else if($data==22) $data = "D75";
      else if($data==255) $data = "Other";
      else $data = "Unknown: ".$data;
    } else if($tag=="9209") { //Flash
      if($data==0) $data = "No Flash";
      else if($data==1) $data = "Flash";
      else if($data==5) $data = "Flash, strobe return light not detected";
      else if($data==7) $data = "Flash, strob return light detected";
      else if($data==9) $data = "Compulsory Flash";
      else if($data==13) $data = "Compulsory Flash, Return light not detected";
      else if($data==15) $data = "Compulsory Flash, Return light detected";
      else if($data==16) $data = "No Flash";
      else if($data==24) $data = "No Flash";
      else if($data==25) $data = "Flash, Auto-Mode";
      else if($data==29) $data = "Flash, Auto-Mode, Return light not detected";
      else if($data==31) $data = "Flash, Auto-Mode, Return light detected";
      else if($data==32) $data = "No Flash";
      else if($data==65) $data = "Red Eye";
      else if($data==69) $data = "Red Eye, Return light not detected";
      else if($data==71) $data = "Red Eye, Return light detected";
      else if($data==73) $data = "Red Eye, Compulsory Flash";
      else if($data==77) $data = "Red Eye, Compulsory Flash, Return light not detected";
      else if($data==79) $data = "Red Eye, Compulsory Flash, Return light detected";
      else if($data==89) $data = "Red Eye, Auto-Mode";
      else if($data==93) $data = "Red Eye, Auto-Mode, Return light not detected";
      else if($data==95) $data = "Red Eye, Auto-Mode, Return light detected";
      else $data = "Unknown: ".$data;
    } else if($tag=="a001") { //ColorSpace
      if($data==1) $data = "sRGB";
      else $data = "Uncalibrated";
    } else if($tag=="a002" || $tag=="a003") { //ExifImageWidth/Height
      $data = $data. " pixels";
    } else if($tag=="0103") { //Compression
      if($data==1) $data = "No Compression";
      else if($data==6) $data = "Jpeg Compression";
      else $data = "Unknown: ".$data;
    } else if($tag=="a217") { //SensingMethod
      if($data==1) $data = "Not defined";
      if($data==2) $data = "One Chip Color Area Sensor";
      if($data==3) $data = "Two Chip Color Area Sensor";
      if($data==4) $data = "Three Chip Color Area Sensor";
      if($data==5) $data = "Color Sequential Area Sensor";
      if($data==7) $data = "Trilinear Sensor";
      if($data==8) $data = "Color Sequential Linear Sensor";
      else $data = "Unknown: ".$data;
    } else if($tag=="0106") { //PhotometricInterpretation
      if($data==1) $data = "Monochrome";
      else if($data==2) $data = "RGB";
      else if($data==6) $data = "YCbCr";
      else $data = "Unknown: ".$data;
    }

  } else if($type=="UNDEFINED") {

    if($tag=="9000" || $tag=="a000" || $tag=="0002") { //ExifVersion,FlashPixVersion,InteroperabilityVersion
      $data="version ".$data/100;
    }
    if($tag=="a300") { //FileSource
      $data = bin2hex($data);
      $data = str_replace("00","",$data);
      $data = str_replace("03","Digital Still Camera",$data);
    }
    if($tag=="a301") { //SceneType
      $data = bin2hex($data);
      $data = str_replace("00","",$data);
      $data = str_replace("01","Directly Photographed",$data);
    }
    if($tag=="9101") {  //ComponentsConfiguration
      $data = bin2hex($data);
      $data = str_replace("01","Y",$data);
      $data = str_replace("02","Cb",$data);
      $data = str_replace("03","Cr",$data);
      $data = str_replace("04","R",$data);
      $data = str_replace("05","G",$data);
      $data = str_replace("06","B",$data);
      $data = str_replace("00","",$data);
    }
  } else {
    $data = bin2hex($data);
    if($intel==1) $data = intel2Moto($data);
  }

  return $data;
}

//================================================================================================
//================================================================================================
// Reads one standard IFD entry
//================================================================================================
//================================================================================================
function read_entry(&$result,$in,$seek,$intel,$ifd_name,$globalOffset) {

  if(feof($in)) { //test to make sure we can still read.
    $result['Errors'] = $result['Errors']+1;
    return;
  }

  //2 byte tag
  $tag = bin2hex(fread( $in, 2 ));
  if($intel==1) $tag = intel2Moto($tag);
  $tag_name = lookup_tag($tag);

  //2 byte datatype
  $type = bin2hex(fread( $in, 2 ));
  if($intel==1) $type = intel2Moto($type);
  lookup_type($type,$size);

  //4 byte number of elements
  $count = bin2hex(fread( $in, 4 ));
  if($intel==1) $count = intel2Moto($count);
  $bytesofdata = $size*hexdec($count);

  //4 byte value or pointer to value if larger than 4 bytes
  $value = fread( $in, 4 );

  if($bytesofdata<=4) {   //if datatype is 4 bytes or less, its the value
    $data = $value;
  } else if($bytesofdata<100000) {        //otherwise its a pointer to the value, so lets go get it
    $value = bin2hex($value);
    if($intel==1) $value = intel2Moto($value);
    $v = fseek($seek,$globalOffset+hexdec($value));  //offsets are from TIFF header which is 12 bytes from the start of the file
    if($v==0) {
      $data = fread($seek, $bytesofdata);
    } else if($v==-1) {
      $result['Errors'] = $result['Errors']+1;
    }
  } else { //bytesofdata was too big, so the exif had an error
    $result['Errors'] = $result['Errors']+1;
    return;
  }
  if($tag_name=="MakerNote") { //if its a maker tag, we need to parse this specially
    $make = $result['IFD0']['Make'];

    if($result['VerboseOutput']==1) {
      $result[$ifd_name]['MakerNote']['RawData'] = $data;
    }
    if(eregi("NIKON",$make)) {
      require_once('makers/nikon.php');
      parseNikon($data,$result);
      $result[$ifd_name]['KnownMaker'] = 1;
    } else if(eregi("OLYMPUS",$make)) {
      require_once('makers/olympus.php');
      parseOlympus($data,$result,$seek,$globalOffset);
      $result[$ifd_name]['KnownMaker'] = 1;
    } else if(eregi("Canon",$make)) {
      require_once('makers/canon.php');
      parseCanon($data,$result,$seek,$globalOffset);
      $result[$ifd_name]['KnownMaker'] = 1;
    } else if(eregi("FUJIFILM",$make)) {
      require_once('makers/fujifilm.php');
      parseFujifilm($data,$result);
      $result[$ifd_name]['KnownMaker'] = 1;
    } else if(eregi("SANYO",$make)) {
      require_once('makers/sanyo.php');
      parseSanyo($data,$result,$seek,$globalOffset);
      $result[$ifd_name]['KnownMaker'] = 1;
    } else {
      $result[$ifd_name]['KnownMaker'] = 0;
    }
  } else if($tag_name=="GPSInfoOffset") {
    require_once('makers/gps.php');
    $formated_data = formatData($type,$tag,$intel,$data);
    $result[$ifd_name]['GPSInfo'] = $formated_data;
    parseGPS($data,$result,$formated_data,$seek,$globalOffset);
  } else {
    //Format the data depending on the type and tag
    $formated_data = formatData($type,$tag,$intel,$data);

    $result[$ifd_name][$tag_name] = $formated_data;

    if($result['VerboseOutput']==1) {
      if($type=="URATIONAL" || $type=="SRATIONAL" || $type=="USHORT" || $type=="SSHORT" || $type=="ULONG" || $type=="SLONG" || $type=="FLOAT" || $type=="DOUBLE") {
        $data = bin2hex($data);
        if($intel==1) $data = intel2Moto($data);
      }
      $result[$ifd_name][$tag_name."_Verbose"]['RawData'] = $data;
      $result[$ifd_name][$tag_name."_Verbose"]['Type'] = $type;
      $result[$ifd_name][$tag_name."_Verbose"]['Bytes'] = $bytesofdata;
    }
  }
}

//================================================================================================
//================================================================================================
// Pass in a file and this reads the EXIF data
//
// Usefull resources
// http://www.ba.wakwak.com/~tsuruzoh/Computer/Digicams/exif-e.html
// http://www.w3.org/Graphics/JPEG/jfif.txt
// http://exif.org/
// http://www.ozhiker.com/electronics/pjmt/library/list_contents.php4
// http://www.ozhiker.com/electronics/pjmt/jpeg_info/makernotes.html
// http://pel.sourceforge.net/
// http://us2.php.net/manual/en/function.exif-read-data.php
//================================================================================================
//================================================================================================
function read_exif_data_raw($path,$verbose) {

  if($path=='' || $path=='none') return;

  $in = @fopen($path, "rb"); //the b is for windows machines to open in binary mode
  $seek = @fopen($path, "rb"); //There may be an elegant way to do this with one file handle.

  $globalOffset = 0;

  if(!isset($verbose)) $verbose=0;

  $result['VerboseOutput'] = $verbose;
  $result['Errors'] = 0;

  if(!$in || !$seek) {  //if the path was invalid, this error will catch it
    $result['Errors'] = 1;
    $result['Error'][$result['Errors']] = "The file could not be found.";
    return $result;
  }

  //First 2 bytes of JPEG are 0xFFD8
  $data = bin2hex(fread( $in, 2 ));
  if($data=="ffd8") {
    $result['ValidJpeg'] = 1;
  } else {
    $result['ValidJpeg'] = 0;
    fclose($in);
    fclose($seek);
    return $result;
  }

  $result['ValidIPTCData'] = 0;
  $result['ValidJFIFData'] = 0;
  $result['ValidEXIFData'] = 0;
  $result['ValidAPP2Data'] = 0;
  $result['ValidCOMData'] = 0;

  //Next 2 bytes are MARKER tag (0xFFE#)
  $data = bin2hex(fread( $in, 2 ));
  $size = bin2hex(fread( $in, 2 ));

  //LOOP THROUGH MARKERS TILL YOU GET TO FFE1 (exif marker)
  while(!feof($in) && $data!="ffe1" && $data!="ffc0" && $data!="ffd9") {
    if($data=="ffe0") { //JFIF Marker
      $result['ValidJFIFData'] = 1;
      $result['JFIF']['Size'] = hexdec($size);

      if(hexdec($size)-2 > 0) {
        $data = fread( $in, hexdec($size)-2);
        $result['JFIF']['Data'] = $data;
      }

      $result['JFIF']['Identifier'] = substr($data,0,5);;
      $result['JFIF']['ExtensionCode'] =  bin2hex(substr($data,6,1));

      $globalOffset+=hexdec($size)+2;

    } else if($data=="ffed") {  //IPTC Marker
      $result['ValidIPTCData'] = 1;
      $result['IPTC']['Size'] = hexdec($size);

      if(hexdec($size)-2 > 0) {
        $data = fread( $in, hexdec($size)-2);
        $result['IPTC']['Data'] = $data ;
      }
      $globalOffset+=hexdec($size)+2;

    } else if($data=="ffe2") {  //EXIF extension Marker
      $result['ValidAPP2Data'] = 1;
      $result['APP2']['Size'] = hexdec($size);

      if(hexdec($size)-2 > 0) {
        $data = fread( $in, hexdec($size)-2);
        $result['APP2']['Data'] = $data ;
      }
      $globalOffset+=hexdec($size)+2;

    } else if($data=="fffe") {  //COM extension Marker
      $result['ValidCOMData'] = 1;
      $result['COM']['Size'] = hexdec($size);

      if(hexdec($size)-2 > 0) {
        $data = fread( $in, hexdec($size)-2);
        $result['COM']['Data'] = $data ;
      }
      $globalOffset+=hexdec($size)+2;

    } else if($data=="ffe1") {
      $result['ValidEXIFData'] = 1;
    }

    $data = bin2hex(fread( $in, 2 ));
    $size = bin2hex(fread( $in, 2 ));
  }
  //END MARKER LOOP

  if($data=="ffe1") {
    $result['ValidEXIFData'] = 1;
  } else {
    fclose($in);
    fclose($seek);
    return $result;
  }

  //Size of APP1
  $result['APP1Size'] = hexdec($size);

  //Start of APP1 block starts with "Exif" header (6 bytes)
  $header = fread( $in, 6 );

  //Then theres a TIFF header with 2 bytes of endieness (II or MM)
  $header = fread( $in, 2 );
  if($header==="II") {
    $intel=1;
    $result['Endien'] = "Intel";
  } else if($header==="MM") {
    $intel=0;
    $result['Endien'] = "Motorola";
  } else {
    $intel=1; //not sure what the default should be, but this seems reasonable
    $result['Endien'] = "Unknown";
  }

  //2 bytes of 0x002a
  $tag = bin2hex(fread( $in, 2 ));

  //Then 4 bytes of offset to IFD0 (usually 8 which includes all 8 bytes of TIFF header)
  $offset = bin2hex(fread( $in, 4 ));
  if($intel==1) $offset = intel2Moto($offset);

  // Check for extremely large values here
  if(hexdec($offset) > 100000) {
      $result['ValidEXIFData'] = 0;
    fclose($in);
    fclose($seek);
    return $result;
  }

  if(hexdec($offset)>8) $unknown = fread( $in, hexdec($offset)-8); //fixed this bug in 1.3

  //add 12 to the offset to account for TIFF header
  $globalOffset+=12;


  //===========================================================Start of IFD0
  $num = bin2hex(fread( $in, 2 ));
  if($intel==1) $num = intel2Moto($num);
  $num = hexdec($num);
  $result['IFD0NumTags'] = $num;

  if($num<1000) { //1000 entries is too much and is probably an error.
    for($i=0;$i<$num;$i++) {
      read_entry($result,$in,$seek,$intel,"IFD0",$globalOffset);
    }
  } else {
    $result['Errors'] = $result['Errors']+1;
    $result['Error'][$result['Errors']] = "Illegal size for IFD0";
  }

  //store offset to IFD1
  $offset = bin2hex(fread( $in, 4 ));
  if($intel==1) $offset = intel2Moto($offset);
  $result['IFD1Offset'] = hexdec($offset);

  //Check for SubIFD
  if(!isset($result['IFD0']['ExifOffset']) || $result['IFD0']['ExifOffset']==0) {
    fclose($in);
    fclose($seek);
    return $result;
  }

  //seek to SubIFD (Value of ExifOffset tag) above.
  $ExitOffset = $result['IFD0']['ExifOffset'];
  $v = fseek($in,$globalOffset+$ExitOffset);
  if($v==-1) {
    $result['Errors'] = $result['Errors']+1;
    $result['Error'][$result['Errors']] = "Couldnt Find SubIFD";
  }

  //===========================================================Start of SubIFD
  $num = bin2hex(fread( $in, 2 ));
  if($intel==1) $num = intel2Moto($num);
  $num = hexdec($num);
  $result['SubIFDNumTags'] = $num;

  if($num<1000) { //1000 entries is too much and is probably an error.
    for($i=0;$i<$num;$i++) {
      read_entry($result,$in,$seek,$intel,"SubIFD",$globalOffset);
    }
  } else {
    $result['Errors'] = $result['Errors']+1;
    $result['Error'][$result['Errors']] = "Illegal size for SubIFD";
  }

  //Check for IFD1
  if(!isset($result['IFD1Offset']) || $result['IFD1Offset']==0) {
    fclose($in);
    fclose($seek);
    return $result;
  }
  //seek to IFD1
  $v = fseek($in,$globalOffset+$result['IFD1Offset']);
  if($v==-1) {
    $result['Errors'] = $result['Errors']+1;
    $result['Error'][$result['Errors']] = "Couldnt Find IFD1";
  }

  //===========================================================Start of IFD1
  $num = bin2hex(fread( $in, 2 ));
  if($intel==1) $num = intel2Moto($num);
  $num = hexdec($num);
  $result['IFD1NumTags'] = $num;

  if($num<1000) { //1000 entries is too much and is probably an error.
    for($i=0;$i<$num;$i++) {
      read_entry($result,$in,$seek,$intel,"IFD1",$globalOffset);
    }
  } else {
    $result['Errors'] = $result['Errors']+1;
    $result['Error'][$result['Errors']] = "Illegal size for IFD1";
  }
  //if verbose output is on, stick in the thumbnail raw data
  if($result['VerboseOutput']==1 && $result['IFD1']['JpegIFOffset']>0 && $result['IFD1']['JpegIFByteCount']>0) {
      $v = fseek($seek,$globalOffset+$result['IFD1']['JpegIFOffset']);
      if($v==0) {
        $data = fread($seek, $result['IFD1']['JpegIFByteCount']);
      } else if($v==-1) {
        $result['Errors'] = $result['Errors']+1;
      }
      $result['IFD1']["ThumbnailData"] = $data;
  }


  //Check for Interoperability IFD
  if(!isset($result['SubIFD']['ExifInteroperabilityOffset']) || $result['SubIFD']['ExifInteroperabilityOffset']==0) {
    fclose($in);
    fclose($seek);
    return $result;
  }
  //seek to InteroperabilityIFD
  $v = fseek($in,$globalOffset+$result['SubIFD']['ExifInteroperabilityOffset']);
  if($v==-1) {
    $result['Errors'] = $result['Errors']+1;
    $result['Error'][$result['Errors']] = "Couldnt Find InteroperabilityIFD";
  }

  //===========================================================Start of InteroperabilityIFD
  $num = bin2hex(fread( $in, 2 ));
  if($intel==1) $num = intel2Moto($num);
  $num = hexdec($num);
  $result['InteroperabilityIFDNumTags'] = $num;

  if($num<1000) { //1000 entries is too much and is probably an error.
    for($i=0;$i<$num;$i++) {
      read_entry($result,$in,$seek,$intel,"InteroperabilityIFD",$globalOffset);
    }
  } else {
    $result['Errors'] = $result['Errors']+1;
    $result['Error'][$result['Errors']] = "Illegal size for InteroperabilityIFD";
  }
  fclose($in);
  fclose($seek);
  return $result;
}

//================================================================================================
//================================================================================================
// Converts a floating point number into a fraction.  Many thanks to Matthieu Froment for this code
//================================================================================================
//================================================================================================
function ConvertToFraction($v, &$n, &$d)
{
  $MaxTerms = 15;         //Limit to prevent infinite loop
  $MinDivisor = 0.000001; //Limit to prevent divide by zero
  $MaxError = 0.00000001; //How close is enough

  $f = $v; //Initialize fraction being converted

  $n_un = 1; //Initialize fractions with 1/0, 0/1
  $d_un = 0;
  $n_deux = 0;
  $d_deux = 1;

  for ($i = 0;$i<$MaxTerms;$i++)
  {
    $a = floor($f); //Get next term
    $f = $f - $a; //Get new divisor
    $n = $n_un * $a + $n_deux; //Calculate new fraction
    $d = $d_un * $a + $d_deux;
    $n_deux = $n_un; //Save last two fractions
    $d_deux = $d_un;
    $n_un = $n;
    $d_un = $d;

    if ($f < $MinDivisor) //Quit if dividing by zero
      break;

    if (abs($v - $n / $d) < $MaxError)
      break;

    $f = 1 / $f; //Take reciprocal
  }
}
?>
